164 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



made by nets of No. 12 or 20 silk towed at depths of 300 fms., but 

 open during both the descent and ascent. The types will be deposited 

 in the United States National Museum, and co-types in the Museum of 

 Comparative Zoology of Harvard College. 



The species described are distributed as follows in the system : — 



DINOFLAGELLIDIA. 

 ADINIDA. 



Prorocentridae. 



1. Prorocentrum curvatum. 



DINIFERIDA. 

 Gymnodinina. 



Pyrocystidae. 



2. Pyrocystis acuta. 4. Pyrocystis semicircularis (Schroder.) 



3. Pyrocystis fusiformis forma 5. Pyrocystis robusta. 



biconica. 



Gymnodinidae. 



6. Pouchetia panamensis. 



Peridinina. 



Ptychodiscidae. 



7. Ptychodiscus carinatus. 



Ceratium schroeteri Schroder. 

 Ceratiuin scapiforme. 

 Ceratium tricarinatum. 

 Peridinium fatulipes. 

 Peridinium grande. 

 Peridinium latissimum. 

 Peridinium longispinum. 

 Peridinium murrayi. 

 Peridinium tenuissimum. 

 Heterodinium agassizi. 

 Heterodinium calvum. 

 Heterodinium curvatum. 

 Heterodinium expansum. 





